KR100385295B1 - Battery-discharge-protection system for electronic accessories used in vehicles containing a battery - Google Patents

Abstract

The present invention measures the energy consumption of a battery powered telephone device to prevent inadvertent overdischarge of the battery of the vehicle by prolonged use of the battery powered telephone device when the vehicle is not running. In a preferred embodiment, the current into the device is measured or estimated gradually from the measurement of other relevant parameters. The gradual measurement of the current is cumulative to yield a total current consumption representing the total energy consumption. At each update after a gradual measurement, the accumulated total is compared with a preset or adaptively determined one. When the total energy consumption is above the threshold, power to the battery powered telephone device is cut off to maintain a sufficient amount of power to start the vehicle and operate other peripheral systems.

Description

BATTERY-DISCHARGE-PROTECTION SYSTEM FOR ELECTRONIC ACCESSORIES USED IN VEHICLES CONTAINING A BATTERY}

Modern technology advances in that many complex electrical accessories are commonly used in passenger vehicles such as passenger cars, cruise ships, or personal aircraft. These accessories include, for example, answering machine cellular telephones and telephone answering machine combinations. As part of such intended functionality, these accessories are typically used or remain powered on when the user leaves the vehicle. In such a situation, these accessories rely on the battery of the vehicle as the power source. Therefore, the use of these accessories increases the possibility of excessively discharging the main battery of the vehicle when the vehicle is not running for a long time. Moreover, because the battery is used to start the vehicle, an over discharged battery is very inconvenient for a user who is unable to start the vehicle. This problem can also be exacerbated when the battery is not fully charged to start up, when the low ambient temperature weakens the battery, or when the battery is old and weak.

The prior art proposes three types of improvements to this problem. The first of these improvements is to simply interrupt power to the battery powered accessory when the vehicle's ignition switch is in the off position. This method has the obvious disadvantage that any accessory, such as an answering machine cellular telephone or answering machine, cannot be used when the vehicle is not in service. This limitation clearly denies the use of these accessories and inconveniences the user of the vehicle.

A second type of improvement proposed by the prior art involves a procedure in which the terminal voltage of the battery of the vehicle is measured and compared with a predetermined voltage threshold below which the battery is excessively discharged. When the terminal voltage of the battery is below this threshold voltage, the power supply to the accessory is interrupted. However, this widely used method has the drawback that the battery is already in a substantially discharged state until a corrective action is taken. Thus, the user of the vehicle may still be inconvenient if the battery is not sufficiently charged to start the vehicle.

A third type of improvement proposed by the prior art involves the use of a timer. By this method, the power supply to the accessory is stopped after a predetermined time after the switching of the vehicle to the ignition off position. However, this improvement only adjusts the single level of current drawn by the battery powered accessories. In other words, the method does not take into account the current draw, which may be different between the accessories or between the operating modes of one accessory and thus discharge the battery at different rates. For example, cellular telephones and answering machines may draw some current when there are no incoming calls. In this state, these accessories can remain powered on for a relatively long time without excessively discharging the battery. On the other hand, a large number of incoming calls indicating a large amount of use generally result in a high average current draw, thus resulting in a generally high battery discharge. This condition needs to cause the power supply to the accessory to stop after a relatively short time to maintain a sufficient amount of charge in the battery. Thus, the dependence of this method on the precondition of constant current makes this method very insufficient in light of the use dependency of current draw of various accessories.

Of course, there is an advantage in the method of protecting the vehicle's battery from excessive discharge due to the battery powered accessories, whereby this method allows the accessory to reach maximum time while maintaining sufficient charge in the battery to start the vehicle. While operating to the same degree as the actual energy consumption or current draw of this accessory.

A further advantage is obtained if the battery discharge protection method adapts to external factors. These external factors may include external ambient temperatures that affect the efficiency of the battery, the life and condition of the battery, or the initial state of charge of the battery. This feature improperly protects the user from battery discharge protection methods by disconnecting and reconnecting the accessory, moving the ignition switch to the accessory position without starting the vehicle, or preventing the vehicle from running for a sufficient time to fully recharge the battery. To prevent bypassing.

FIELD OF THE INVENTION The present invention relates to a protective device for a vehicle, in particular an electrical accessory, such as a telephone accessory, for a vehicle comprising a battery to maintain a minimum charge of the battery when powered by the battery while the vehicle is not running. A battery discharge protection system used.

1 is a block diagram of a battery discharge protection system and an electrical system of a vehicle.

2 is a block diagram illustrating one embodiment of a current sensor.

3 is a flow chart showing logic used by the control unit of the battery discharge protection system.

4 is a block diagram of the present invention showing the adaptability of a battery discharge protection system to include a power bus to facilitate operation of a multi-telephone accessory and to include an adaptive threshold input for varying the magnitude at which such accessory will discharge the battery. .

5 is a block diagram of the present invention showing the adaptability of a battery discharge protection system to a telephone accessory operating in a discrete power state where the telephone accessory has a known priori power consumption.

6 is a flow diagram showing logic used by a control unit in which battery discharge is determined based on the power state of the accessory.

The present invention measures and regulates the consumption of battery powered accessories to prevent inadvertently overdischarging the vehicle's battery by prolonged use of the accessory when the vehicle is not running. The current drawn by the accessory is measured periodically or estimated from other measurements or from the knowledge of other relevant parameters. Periodic measurements of current are accumulated to yield an estimate of battery discharge caused by the accessory. Upon updating each discharge estimate, the accumulated total is compared to a preset or adaptively determined threshold that sets a boundary for the limit at which the accessory will discharge the battery. When the discharge estimate is above the threshold, power to the battery powered accessory is stopped.

Power is not returned to the battery powered accessory until the system detects a current flow from the alternator to the battery of the vehicle indicating that the engine is running and the battery is recharging. In this regard, turning off the engine results in the cycle repeating. However, the battery cannot be fully recharged. Thus, the system is provided with an adaptive threshold input that can detect the state of charge of the battery and adjust the threshold level accordingly.

Referring now to the drawings, FIG. 1 shows a basic embodiment of the battery discharge protection system of the present invention, indicated generally by reference numeral 10. The battery discharge protection system 10 is particularly suitable for providing an interface between the vehicle's electrical system indicated by reference numeral 60 and the battery powered telephone accessory indicated by reference numeral 100. Examples of telephone accessory 100 include a cellular telephone or telephone answering machine. The system 10 may be provided as part of the vehicle's electrical system, as a standalone adapter for one battery powered telephone accessory or multitelephone accessory, or as an integral part of a particular battery powered telephone accessory. In either case, power from the vehicle's battery is passed through the system 10 to power the telephone accessory 100. Essentially, the function of the battery discharge protection system 10 is to monitor the discharge of the battery by the telephone accessory 100 when the alternator of the vehicle does not recharge the battery. When telephone accessory 100 discharges the battery by any amount, system 10 suspends power to accessory 100 to prevent operation of accessory 100 from excessively discharging the battery.

A general example of the function of the battery discharge protection system is illustrated by the use of an answering machine telephone and telephone answering machine combination powered by a connection to the vehicle's electrical system. If the car is left unattended for a long time, such as when the owner is on a long business trip, the telephone and answering machine combination has the potential to overdischarge the battery, thereby making the battery unable to start the car. . When the battery discharge protection system is used as the interface between the vehicle and the telephone and answering machine combination, the actual amount of battery discharged by these accessories is estimated. The system accomplishes this function by measuring the battery current to the telephone accessory and then calculating the amount of discharge as a function of the sensed current. The system interrupts or disconnects power to the accessory when the accessory discharges the battery by a predetermined amount. The intention of such a power interruption design is to maintain a charge level of the battery sufficient to start the vehicle or to operate other critical systems such as a car alarm system and to prevent damage due to repeated transient discharges of the battery.

In a preferred embodiment, the battery discharge protection system 10 includes an accessory current sensor 20, an enable switch 30, an alternator current sensor 35, a control unit 40 and an accumulator 45. The electrical system of the vehicle 60 is more fully represented by the battery 70 and the alternator 80. The accessory current sensor 20 measures the current to the telephone accessory 10. Enable switch 30 controls the flow of current to telephone accessory 100. The alternator current sensor 35 senses the presence of a recharge current flow from the alternator 80 to the battery 70 to indicate that the vehicle is in operation and provides an input to the control unit 40. The control unit 40 monitors the battery discharge caused by the accessory 100 to control the position of the enable switch 30. Accumulator 45 stores the running sum of a sample of the current flow to telephone accessory 100.

The telephone accessory 100 is electrically connected to the battery 70 of the vehicle in series with the accessory current sensor 20 and the enable switch 30. When the enable switch 30 is in the closed position, current is delivered to the telephone accessory 100 through the accessory current sensor 20. Conversely, when the enable switch 30 is in the open position, current to the telephone accessory 100 is interrupted.

An embodiment of accessory current sensor 20 is shown in more detail in FIG. 2. As shown in FIG. 2, accessory current sensor 20 includes sense resistor 22, differential amplifier 24, and analog-to-digital (A / D) converter 26. The current from the battery 70 of the vehicle passes through the sense resistor 22. The differential amplifier 24 senses the voltage drop across the sense resistor 22.

Those skilled in the art will readily understand that the output of differential amplifier 24 is directly proportional to the current flowing through sense resistor 22. The output of the differential amplifier 24 is passed to an analog-to-digital converter 26 to convert the output of the differential amplifier 24 into a digital code word that can be interpreted by the control unit 40 at each sampling time.

Referring again to FIG. 1, an alternator current sensor 35 outputs the output of the alternator 80 in the vehicle electrical system 60 to detect the presence of a recharge current from the alternator 80 to the battery 70. (lead) is connected. The alternator current sensor 35 is connected to the control unit 40 of the battery discharge protection system 10, which is directly powered from the battery 70. In addition, the control unit 40 is further connected to the accessory current sensor 20, the enable switch 30 and the accumulator 45. The control unit 40 has the ability to generate control signals directed to both the enable switch 30 and the accessory current sensor 20. The enable switch 30 opens or closes the enable switch 30 in response to a control signal generated by the control unit 40. In general, the alternator current sensor 35 indicates that a recharge current is present in the control unit 40, and the control unit 40 sends a set signal that causes the enable switch 30 to close. Occurs on). Subsequently, when the alternator current sensor 35 determines that there is no recharge current, and the control unit 40 detects that the enable switch 30 is in the closed position, the control unit 40 stores the battery 70. To measure the current flow from the phone accessory 100 to the telephone accessory 100.

The control unit 40 triggers the enable line of the analog-to-digital converter 26 in the accessory current sensor 20 to effect measurement of the current to the telephone accessory 100, and the accessory current sensor 20 detects the sensed current. Is returned to the control unit 40. The control unit 40 adds the sampled value to the total held in the accumulator 45. Any subsequent measurement of current is performed at periodic intervals after the initial measurement and added to the value stored in accumulator 45. After each summation of the current measurements in accumulator 45, control unit 40 compares the value stored in accumulator 45 with a predetermined threshold. By regular comparison of the accumulated current samples with the threshold, the withdrawal of the accessory is monitored and the operation of the accessory is constantly checked to ensure that the battery of the vehicle is not over discharged.

The predetermined threshold of discharge from the battery can be determined empirically by experiments with various vehicles, batteries, conditions, and the like. On the other hand, the threshold can be set as a general value for all states, such as the difference between the total charge capacity of a typical battery versus the worst-case demand imposed by starting the vehicle's engine. For example, a typical battery may have a rated capacity of 60 amp-hours. In the worst case, approximately 50 amp-hours from the battery may be needed to power the starter to start the engine of the vehicle. In other words, the starting device and the rating system can draw 600 amps for up to 5 minutes to start the engine, especially the engine requiring a glow-plug. Thus, the threshold can theoretically be set at 10 amp-hours. However, other systems of the vehicle, such as alarm systems, may require uninterpreted power, and thresholds must be adjusted to compensate for the energy needed to operate these systems. Furthermore, it may be desirable to include a working margin or factor of safety in setting the threshold. Thus, in this example the acceptable threshold may be 5 amp-hours provided a safety factor of two. In other words, 10 amp-hours can be discharged from the battery leaving enough energy to start the vehicle, but half or 5 amp-hours of that amount provide a safety factor of 2. Assuming a typical telephone accessory can draw current at approximately mA, this threshold is sufficient to enable the accessory's operation for a significant period of time.

If the value in the accumulator 45 is smaller than the threshold value, the control unit 40 continues to carry out the current measurement at periodic intervals. Each result sample is added to the previous value stored in accumulator 45. When the value in the accumulator 45 is above the threshold, the control unit 40 generates a reset signal that opens the enable switch 30 and stops supplying power to the telephone accessory 100. At the same time, the control unit 40 clears the accumulator 45 by setting the stored value to zero.

When the recharge current is detected by the control unit 40, power is returned to the telephone accessory 100. That is, when the alternator 80 is recharging the battery 70 or the engine of the vehicle is in operation, the alternator current sensor 35 indicates to the control unit 40 that a recharge current is present. The control unit 40 generates a setting signal for closing the enable switch 30 and returning power to the telephone accessory 100.

Referring now to FIG. 3, a flowchart shows the operation of the control unit 40 of the battery discharge protection system 10. When the process begins (block 200), enable switch 30 is open and does not deliver current to telephone accessory 100. When the recharge current is sensed by the alternator current sensor 35 (block 205), the control unit 40 generates a set signal closing the enable switch 30 to control the flow of current to the telephone accessory 100. Enable (block 210) and start its internal clock (block 215). After initiating its clock, control unit 40 waits a predetermined time (block 220) and determines whether a recharge current is present (block 225). At this time, since the battery 70 is continuously recharged by the alternator 80, the control unit 40 continuously loops until there is no recharge current.

Upon notifying that no recharge current is present, the control unit 40 starts sampling current through the accessory current sensor 20 to the telephone accessory 100 at regular intervals of the elapsed time indicated by the internal clock. When the clock signal is generated, control unit 40 measures current at accessory current sensor 20 (block 230). The control unit 40 adds the value of the current sample to the value stored in the accumulator 45 (block 240). At this time, the control unit 40 compares the update value just stored in the accumulator 45 with a threshold, ie a limit imposed so that the accessory 100 can discharge the battery (block 245).

If the value in the accumulator 45 is less than the threshold and the control unit 40 is informed by the alternator current sensor 35 that a recharge current is present (block 250), the control unit 40 may accumulate the accumulator 45. ) (Block 255). When the absence of the recharge current is detected again, the control unit 40 starts a new current measurement process (block 220). However, if the presence of a recharge current has not been detected since the previous measurement (block 250), the control unit 40 does not reset the accumulator 45 but waits for the next sampling time (block 220). Second and any subsequent sampling values of current are added to the previous sum stored in accumulator 45 (block 240). In addition, after each new sample is added to the accumulator 45, the control unit 40 compares the accumulated stored value with a predetermined threshold (block 245).

When the accumulated value stored in the accumulator 45 is greater than or equal to the threshold (block 245), the control unit 40 resets the value in the accumulator to zero (block 260) and reset signal to open the enable switch 30. (Block 265), power to the telephone accessory 100 is interrupted.

Referring now to FIG. 4, the system 10 described above may also be applied to a vehicle that includes a power bus 90. In this configuration, the power bus 90 is connected to the battery 70 in series with the accessory current sensor 20 and the enable switch 30. Power bus 90 includes a plurality of connection points to regulate multiple accessories 100. For example, cellular telephones, telephone answering machines, and fax machines can all be connected to the power bus 90 to enable it to operate with the power provided by the battery 70. Here, the system 10 measures the current to the power bus 90. Thus, the system 10 estimates the battery discharge from the current measurement on the power bus 90, and the complete discharge is independent of the telephone accessory 100 being operated. This concept of power bus 90 can be extended to situations where a plurality of telephone accessories 100 can be linked by a common power bus and a command and control bus, where one of the accessories is connected to the other of the accessories. Provide power and control center for it. As long as the total current to these telephone accessories 100 can be measured or estimated, the system 10 can fulfill the intended purpose.

Another feature shown in FIG. 4 that may be included in the battery discharge protection system 10 is an adaptive threshold input, indicated by reference numeral 50. The adaptive threshold input 50 provides a means to more accurately control the amount of discharge that may be caused by the accessory 100. The adaptive threshold input 50 can take many forms. For example, it is known that low ambient temperatures inhibit the battery's chemical reaction and effectively reduce the amount of power available from the battery. It is also known that many modern vehicles are equipped with a temperature measuring device which displays the external ambient temperature to the owner of the vehicle. In this situation, the adaptive threshold input 50 is connected to the temperature measuring device of the vehicle to adjust the threshold of allowed discharge of the battery 70 as a function of the external ambient temperature. Still other examples include an adaptive threshold input 50 that compensates for the life of the battery 70, changes the threshold in accordance with the amount of recharging to the battery following a discharge cycle, or sets the threshold based on an actual measurement of the state of charge of the battery. ) May be included.

In addition, it is important that the configuration of the battery discharge protection system 10 as shown in Figs. 1, 4 and 5 can take a different form. For example, the system 10 can be included in the accessory 100, where a wire connection facilitates interrelation with the electrical system of the vehicle 60. In a second form, the system 10 can be connected by wiring to a cradle that is connected to a vehicle, where the cradle is generally configured to receive a particular telephone accessory 100 or a telephone accessory 100. Can be. Alternatively, the system 10 may be a general or specific adapter that forms an interface between the accessory 100 and the electrical system of the vehicle 60. For example, the cradle / adapter comprising the system 10 connects to the electrical system of the vehicle 60 via a port. At the same time, the cradle / adapter is equipped with either a socket for a cigarette lighter plug from the accessory 100 or a connector equipped with a power input port of a particular accessory 100. In a third form, the system 10 is part of a common power and command and control bus that links a plurality of accessories 100 as described above. Also in a fourth form, the system 10 can be wholly present in the electrical system of the vehicle 60 itself.

Referring now to FIG. 5, another embodiment of a battery discharge protection system 10 is shown, wherein a portion of the system 10 is included within the accessory 100 itself. In this configuration, the accessory 100 is known to operate in a specified number of discrete power states, and the energy consumption of the accessory 100 in each state is also known. The calculation of energy consumption is simply a matter of the power state in which the phone accessory 100 is operating and the amount of time spent by the phone accessory 100 in this power state. The total energy consumed is calculated by summing the energy consumption in each operating state of the phone accessory 100. Since energy consumption is related to battery discharge by the terminal voltage of the battery taken to remain approximately constant, in this embodiment, energy consumption is used as a substitute for discharge.

As an example of this concept, an AMPS cellular telephone operates under an RF transmit power control algorithm, and the base station to which the telephone is connected instructs the telephone to adjust its RF level according to the estimated RF link loss. For Class III AMPS cellular telephones, the following seven distinct operating power states are valid: (1) reception; (2) transmit at power level 0, 1, or 2; (3) transmit at power level 3; (4) transmit at power level 4; (5) transmit at power level 5; (6) transmit at power level 6; (7) transmit at power level 7. In each of these operating power states, the phone consumes energy at different rates. Therefore, under the power control algorithm, the energy consumption rate of the telephone in each state is known a priori. Thus, the total energy consumed by the telephone can be calculated by determining the operating state of the telephone and the amount of time spent by the telephone in each operating state.

As shown in FIG. 5, this configuration does not require an accessory current sensor 20 in the battery discharge protection system 10. The telephone accessory 100 is supplied with power through a serial connection with the enable switch 30 to the battery 70. Here, the accessory 100 includes a base accessory 110 and a power state detector 120. The power state detector 120 determines the operating state of the base accessory 110 and is connected to the control unit 40 of the system 10.

By this structure, the system 10 also performs a periodic comparison between the threshold and the energy consumed by the telephone accessory 100. The comparison between the energy consumed and the threshold is triggered by a change in operating state or a predetermined amount of time spent in a single power state. The control unit 40 performs the measurement and maintains the continuous total energy consumed by the accessory 100 in the accumulator 45. After each summation, the value in accumulator 45 is compared with a threshold. The reset signal is generated when the value in the accumulator 45 is above the threshold.

Referring now to FIG. 6, a flowchart shows the operation of control unit 40 of another embodiment of battery discharge protection system 10 as shown in FIG. 5. When the process is initiated (block 300), enable switch 30 is open to not deliver current to telephone accessory 100. When the recharge current is sensed by the alternator current sensor 35 (block 305), the control unit 40 generates a set signal that closes the enable switch 30 to control the flow of current to the telephone accessory 100. Enable (block 310) and start its internal clock (block 315). After initiating its clock, control unit 40 waits for a predetermined time (block 320) and determines whether a recharge current is present (block 325). If there is a recharge current at this time, since the battery 70 is continuously recharged by the alternator 80 of the electrical system of the vehicle 60, the control unit 40 will no longer have a recharge current. Until it loops continuously.

When notified that no recharge current is present, the control unit 40 monitors the power state of the device 100 via the power state detector 120 at regular intervals of elapsed time indicated by the internal clock. Begin (block 330). When the clock signal is generated, the control unit 40 determines the power state of the device 100 (block 330). The control unit 40 calculates the energy consumption during the sampling time and adds the value to the value stored in the accumulator 45 (block 340). The control unit 40 then compares the update value just stored in the accumulator 45 with a threshold, ie a limit imposed so that the accessory 100 can discharge the battery (block 345).

If the value in the accumulator 45 is less than the threshold and the control unit 40 is informed by the alternator current sensor 35 that a recharge current is present (block 350), the control unit 40 may accumulate the accumulator 45. ) (Block 355). When it is again detected that there is no recharge current, the control unit 40 starts a new power state calculation process (block 320). However, if the presence of the recharge current is not detected after the previous measurement (block 350), the control unit 40 does not reset the accumulator 45 but simply waits for the next sampling time (block 320). The second and any subsequent sampling values of energy consumed are added to the previous sum stored in accumulator 45 (block 340). In addition, after each new sample is added to the accumulator 45, the control unit 40 compares the accumulated stored value with a predetermined threshold (block 345).

When the accumulated value stored in the accumulator 45 is equal to or greater than the threshold value (block 345), the control unit 40 resets the value in the accumulator to zero (block 365), and reset signal for opening the enable switch 30. (Block 370), power to the telephone accessory 100 is interrupted.

The invention may, of course, be carried out in a particular manner other than as shown herein without departing from the spirit and essential features of the invention. Accordingly, it is to be understood that the embodiments of the present invention are intended to be illustrative and not intended to be limiting, and include all modifications that are within the meaning and equivalence of the appended claims.

Claims (32)

In a battery discharge protection system for a mobile telecommunication device powered by a battery: a power supply line connecting the telecommunication device to a battery of a vehicle; b) monitor the current consumed by the telecommunication device, Iii) an accessory current sensor for determining the current consumed by the telecommunication device at discrete time intervals; Ii) an accumulator for summing the current consumed by the telecommunication device during the plurality of time intervals to obtain a total accumulated current consumed; Iii) a control unit comprising means for generating a control signal when the total current consumed as represented by the cumulative total reaches a threshold; c) a power switch disposed in said power supply line between said battery and said telecommunications device and efficiently connected to said control unit, said power switch for interrupting power to said telecommunications device in response to said control signal from said control unit; Battery discharge protection system comprising a. 10. The system of claim 1, further comprising an alternator current sensor input connected to the control unit, the control unit starting to monitor the amount of current consumed when no recharge current is present in response to the alternator current sensor. Battery discharge protection system, characterized in that. The battery discharge protection system according to claim 1, wherein the control unit is included in the telecommunication device. The battery discharge protection system according to claim 1, wherein said control unit is included in an adapter connected to said telecommunication device. The battery discharge protection system of claim 1, wherein the control unit is included in a vehicle electrical system. The battery discharge protection system of claim 1, further comprising a power bus connecting a plurality of devices to the power line, wherein the control unit monitors current flow through the power bus. 2. The battery discharge protection system of claim 1, wherein the threshold is determined adaptively. 8. The battery discharge protection system of claim 7, wherein the threshold is determined adaptively as a function of ambient temperature. 8. The battery discharge protection system of claim 7, wherein the threshold is determined adaptively as a function of battery condition. In a battery discharge protection system for a mobile telecommunication device powered by a battery: a power supply line connecting the telecommunication device to a battery of a vehicle; b) monitor battery discharge caused by the telecommunications device, Iii) an accessory current sensor for measuring a current flowing through the power supply to the telecommunication device at discrete time intervals; Ii) an accumulator for storing the total cumulative current consumed by the telecommunication device; Iii) a control unit comprising means for generating a control signal when the current consumed by the device reaches a threshold as represented by the cumulative total; c) a power switch disposed in said power supply line between said battery and said telecommunications device and efficiently connected to said control unit, said power switch for interrupting power to said telecommunications device in response to said control signal from said control unit; Battery discharge protection system comprising a. 11. The method of claim 10, further comprising an alternator current sensor connected to the input of the control unit, wherein the control unit begins to monitor the amount of current consumed when no recharge current is present in response to the alternator current sensor. Battery discharge protection system, characterized in that. 11. A battery discharge protection system according to claim 10, wherein said control unit is included in said telecommunication device. 11. A battery discharge protection system according to claim 10, wherein said control unit is contained within an adapter connected to said telecommunication device. 11. The battery discharge protection system of claim 10, wherein the control unit is included in a vehicle electrical system. 11. The battery discharge protection system of claim 10, further comprising a power bus that connects a plurality of accessories to the power line, wherein the control unit monitors a current flowing through the power bus. 11. The battery discharge protection system of claim 10, wherein said threshold is determined adaptively. 17. The battery discharge protection system of claim 16, wherein the threshold is determined adaptively as a function of ambient temperature. 17. The battery discharge protection system of claim 16, wherein the threshold is determined adaptively as a function of battery condition. In a battery discharge protection system for a mobile telecommunication device powered by a battery and having a plurality of power states, the power consumed varies based on the power state: a power supply line connecting the mobile telecommunication device to a battery of a vehicle; b) monitor the energy consumed by the mobile telecommunication device, Iii) a power state detector for determining a power state of the mobile telecommunication device; Ii) a processor that calculates energy consumed by the mobile telecommunication device in each power state; Iii) an accumulator for maintaining a total cumulative energy consumed by said mobile telecommunication device; Iii) a control unit comprising means for generating a control signal when the total energy consumed as indicated by the cumulative total reaches a threshold; c) a power switch disposed in said power supply line between said battery and said telecommunications device and efficiently connected to said control unit, said power switch for interrupting power to said telecommunications device in response to said control signal from said control unit; Battery discharge protection system comprising a. 20. The apparatus of claim 19, further comprising an alternator current sensor connected to the input of the control unit, wherein the control unit begins to monitor the amount of energy consumed when no recharge current is present in response to the alternator current sensor. Battery discharge protection system, characterized in that. 20. A battery discharge protection system according to claim 19, wherein said control unit is included in said telecommunication device. 20. A battery discharge protection system according to claim 19, wherein said control unit is contained within an adapter connected to said telecommunication device. 20. The battery discharge protection system of claim 19, wherein the control unit is included in a vehicle electrical system. 20. The battery discharge protection system of claim 19, wherein said threshold is determined adaptively. 25. The battery discharge protection system of claim 24, wherein the threshold is determined adaptively as a function of ambient temperature. 25. The battery discharge protection system of claim 24, wherein the threshold is determined adaptively as a function of battery condition. A method of preventing a telecommunication device from excessively discharging a battery in a vehicle when the vehicle does not charge the battery: a) determining the current consumed by the telecommunication device at discrete time intervals; b) summing the current consumed by the telecommunication device during the plurality of time intervals to determine a cumulative total of current consumed; c) periodically comparing the current consumed as represented by the cumulative total with a threshold; d) stopping the current to the telecommunication device when the current consumed exceeds the threshold, wherein the telecommunication device is prevented from excessively discharging the battery in the vehicle. 28. The method of claim 27, wherein determining the current consumed by the telecommunication device comprises sampling and accumulating current to the telecommunication device. To prevent the battery from discharging quickly. 28. The method of claim 27, wherein determining the current consumed by the telecommunications device comprises: determining a power state of the telecommunications device; determining an amount of time when the telecommunications device is in the power state And calculating a current consumed as a function of the power state and time. 20. A method of preventing a telecommunications device from excessively discharging a battery in a vehicle. 28. The method of claim 27, further comprising the step of adapting and determining the threshold value to prevent the telecommunication device from excessively discharging the battery in the vehicle. 31. The method of claim 30, wherein the threshold is determined adaptively as a function of ambient temperature. 31. The method of claim 30, wherein the threshold is determined adaptively as a function of battery condition.